Tool for locally forming a workpiece

ABSTRACT

A forming or re-rounding machine has a pair of concentric inner and outer rings supported with a gap between the rings. The support of the rings provides for both axial and rotational movement. A can or shell having a section to be formed, or a damaged portion for re-rounding, is inserted into the gap. Hydraulic rams are mounted in a radial pattern into the outer edge of the inner ring and the inner edge of the outer ring, facing the gap. The inner and outer rings can be oriented so that the hydraulic rams in each ring can be directly opposed to the hydraulic rams in the opposing ring, or alternatively, can be offset from adjacent hydraulic rams in the opposing ring. In a vertically oriented embodiment, the forming or re-rounding machine has a pair of concentric rings suspended from a crane or I-beam support with a gap between the rings.

FIELD AND BACKGROUND OF THE INVENTION

[0001] The present invention relates generally to the field of forming or re-rounding metal cans and shells and in particular to a new and useful hydraulic forming tool for providing a damaged cylinder with a round shape.

[0002] Relatively large metal shells and cans are used in a wide variety of applications including use as coverings to protect mechanical and electrical devices and provide a uniform appearance, and as components of thick-walled pressure vessels. Often, these shells and cans must be formed to have a perfectly round, or circular, shape in order to fit as intended.

[0003] For a general description of methods of making pressure vessels, the reader is referred to Chapters 38 and 52 of Steam/Its Generation and Use, 40th Edition, The Babcock and Wilcox Company, Barberton, Ohio, U.S.A., ©1992, the text of which is hereby incorporated by reference as though fully set forth herein.

[0004] In addition, metal shells and cans can become deformed due to contact with heavy objects or from damage that occurs during manufacturing or shipping. As a result, it is necessary to re-form the shells and cans into a perfectly round cylinder again.

[0005] Prior methods for forming or re-rounding metal shells and cans include hitting the cans with an uncontrolled hammer, rolling or re-rolling the cans in a rolling machine and pressing the shell or can from the inside curvature with a single post and ram device.

[0006] The prior methods and devices are unsatisfactory because they are inaccurate and can affect other regions of the cans and shells besides those being re-rounded. Flexing of the entire can, including areas not being formed or re-rounded, can occur as a result of using each of the prior devices, since a small area cannot be worked in isolation. As a result, one can end up chasing a deformation around the can in what is known as “radial chasing.” (So-called “axial chasing”, along the length of the can, tends to be minimal.) Further, prior devices require significant mechanical force, especially to form or re-round large, thick-walled cans. As a result, the prior devices are somewhat unsafe due to the nature of the forces being applied to the cans and shells.

SUMMARY OF THE INVENTION

[0007] It is an object of the present invention to provide a forming or re-rounding machine which is safer to use than known machines.

[0008] A further object of the invention is to provide a forming or re-rounding machine which does not adversely affect other sections of a can or shell being formed or re-rounded.

[0009] In one embodiment, the machine for forming a workpiece has a single set of concentric inner and outer rings which can be independently moved back and forth along and rotated about a damaged can to align one of the hydraulic rams on the appropriate side of the damaged can to contact a damaged area. Once the rings are positioned, the aligned one of the hydraulic rams is activated to press the can wall back into round. Accordingly, a machine for forming a workpiece is provided having a pair of concentric rings and a support connected to each of the rings, with a gap between the rings. One ring is an inner ring, the other is an outer ring. The support includes means for rotating the rings about the ring axis and means for moving the rings back and forth along the ring axis. A can or shell having a portion to be formed or a damaged portion for re-rounding is inserted into the gap. Hydraulic rams are mounted into the outer edge of the inner ring and the inner edge of the outer ring, facing the gap. The inner and outer rings can be oriented so that the hydraulic rams in each ring can be directly opposed to the hydraulic rams in the opposing ring, or alternatively, can be offset from adjacent hydraulic rams in the opposing ring.

[0010] In another embodiment, the machine has multiple sets of concentric inner and outer rings which can be rotated using the support. This embodiment of the machine has a reduced need for movement back and forth along the ring axis, because one of the hydraulic rams in any one of the multiple sets of rings can be quickly aligned over the damaged area of the can.

[0011] In a vertical embodiment, a forming or re-rounding machine has a single set of concentric inner and outer rings which can be raised, lowered and rotated about a damaged can to align one of the hydraulic rams on the appropriate side of the damaged can to contact a damaged area. Accordingly, a vertically oriented forming or re-rounding machine is provided having a pair of concentric rings suspended from a crane, or beam support, or other vertically movable support, with a gap between the rings. One ring is an inner ring, the other is an outer ring. A can or shell having a damaged portion for re-rounding is inserted into the gap. Hydraulic rams are mounted horizontally into the outer edge of the inner ring and the inner edge of the outer ring, facing the gap. The inner and outer rings can be oriented so that the hydraulic rams in each ring can be directly opposed to the hydraulic rams in the opposing ring, or can instead, be offset from adjacent hydraulic rams in the opposing ring.

[0012] In a horizontal embodiment, the forming or re-rounding machine has a single set of concentric inner and outer rings which can be moved right and left and rotated about a damaged can to align one of the hydraulic rams on the appropriate side of the damaged can to contact a damaged area. Accordingly, a horizontally oriented re-rounding machine is provided having a pair of concentric rings supported by a horizontally movable support, with a gap between the rings. One ring is an inner ring, the other is an outer ring. A can or shell having a damaged portion for re-rounding is inserted into the gap. Hydraulic rams are mounted vertically into the outer edge of the inner ring and the inner edge of the outer ring, facing the gap. The inner and outer rings can be oriented so that the hydraulic rams in each ring can be directly opposed to the hydraulic rams in the opposing ring, or can instead, be offset from adjacent hydraulic rams in the opposing ring.

[0013] The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which a preferred embodiment of the invention is illustrated.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In the drawings:

[0015]FIG. 1 is a cross sectional view of a forming or re-rounding machine of the invention illustrating the position of a can being formed or re-rounded in phantom lines;

[0016]FIG. 2 is a side elevational view of a vertical embodiment of the forming or re-rounding machine of FIG. 1;

[0017]FIG. 3 is a side elevational view of an alternate embodiment of the forming or re-rounding machine of FIG. 2;

[0018]FIG. 4 is a side elevational view of a horizontal embodiment of the forming or re-rounding machine of FIG. 1; and

[0019]FIG. 5 is a cross sectional view of an alternative to the horizontal embodiment of FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Referring now to the drawings, in which like reference numerals are used to refer to the same or similar elements, FIGS. 1 and 2 show a machine 10 for forming or re-rounding a workpiece 100, such as a cylindrical can or metal shell, having a pair of concentric rings 20, 25. One ring is an inner ring 20, while the other is an outer ring 25. A gap 40 is formed between the rings 20, 25.

[0021] Each of the inner and outer rings 20, 25 carries several hydraulic rams 60, 80, respectively. The hydraulic rams 60, 80 are oriented in a radial pattern within the respective rings 20, 25. Inner hydraulic rams 60 are arranged to extend from the outer edge of the inner ring 20, while outer hydraulic rams 80 are positioned to extend into gap 40 from the inner edge of outer ring 25.

[0022] Each hydraulic ram 60, 80 has a hydraulic cylinder 50 and a ram head 70 connected to the cylinder by bolt connector 72. Hydraulic feeds 74 are used to supply and remove a hydraulic pressure for each of the hydraulic cylinders 50.

[0023] In each embodiment described below, a workpiece 100 is positioned next to the rings 20, 25, and the rings are moved along the ring axis so that the workpiece 100 ends up within gap 40 having inner ring 20 on the inside of the can 100 and outer ring 25 on the outside of the can 100. An operator then positions the hydraulic rams 60, 80 within the rings 20, 25 along the ring axis and circumferentially about the ring axis to align at least one hydraulic ram 60, 80 over an area of the can 100 to be formed or re-rounded. Once the hydraulic ram 60, 80 is aligned, the operator may leave the area, and the selected one(s) of the hydraulic rams 60, 80 is fired by supplying and subsequently removing hydraulic pressure to cylinders 50 through feeds 74. The ram head 70 impacts the appropriate side of the can 100 and re-rounds the damaged region.

[0024] The ring arrangement of the forming or re-rounding machine 10 permits rapid positioning of the hydraulic rams 60, 80. Further, the rings 20, 25 may be positioned by a local operator, or a remote operator. The hydraulic rams 60, 80 are not activated and do not need to be loaded until all of the operators have left the immediate area, thereby increasing the safety of using the forming or re-rounding machine 10 of the invention over known devices.

[0025] For the vertical orientation depicted in FIG. 2, the inner and outer rings 20, 25 are suspended from a support 110 by cables 90 and rods 95. Rods 95 are connected to each of several support pins 30 in each of the inner and outer rings 20, 25. The support 110 may be attached to a crane beam 120 or other structure which is used to raise and lower the support 110 and attached inner and outer rings 20, 25. The support 110 can rotate, so that rings 20, 25 also rotate in order to position the hydraulic rams 60, 80 at different positions on the circumference of a workpiece 100 at a given vertical displacement.

[0026] Although FIGS. 1 and 2 show rings 20, 25 positioned in the same plane with hydraulic rams 60, 80 staggered about the circumference, rings 20, 25 may be positioned one above the other and/or hydraulic rams 60, 80 may arranged about the circumference as required.

[0027]FIG. 3 illustrates an alternative embodiment requiring less vertical movement of the rings 20, 25 to position the hydraulic rams 60, 80. Multiple sets of inner and outer rings 20, 25 are provided connected together using rods 95 and supported from support 110. Inner rings 20 may be moved independently from outer rings 25, and vice versa.

[0028]FIG. 4 illustrates another embodiment of the invention in which the workpiece 100 is handled in the horizontal plane. In this embodiment hydraulic rams are mounted vertically into the outer edge of the inner rings 20 and the inner edge of the outer rings 25, facing the gap 40. Similar to the vertical embodiment, the support 110 can rotate, so that rings 20, 25 also rotate in order to position the hydraulic rams 60, 80 at different positions on the circumference of a workpiece 100 at a given horizontal displacement. For some applications it may be desirable or necessary to segment or split outer rings 25 to get over or around exterior support structure, and then reconnect outer rings 25 as required.

[0029] A variation of the horizontal embodiment is shown in FIG. 5. In this embodiment the outer ring 25′ is shaped more or less like the letter “C.” Outer ring 25′ only partially surrounds workpiece 100, thus allowing forming or re-rounding machine 10 to clear any support mechanism.

[0030] While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles. For example workpiece 100 could be rotated instead of rotating any or all of the inner and outer rings. 

What is claimed is:
 1. A machine for forming a workpiece, comprising: an inner ring; an outer ring concentric with and surrounding the inner ring about an axis to form a gap between the inner and outer rings, the gap for receiving the workpiece between the inner and outer rings; at least a pair of hydraulic rams, at least one hydraulic ram mounted to each of the inner and outer rings so as to extend into the gap; and a support connected to each of the inner and outer rings for moving the inner and outer rings back and forth along the axis and rotating the inner and outer rings about the axis to align at least one of the at least a pair of hydraulic rams over an area of the workpiece.
 2. The machine according to claim 1, wherein each hydraulic ram comprises an hydraulic cylinder connected to a ram head.
 3. The machine according to claim 1, wherein the inner and outer rings are oriented so that the at least one hydraulic ram mounted to the inner ring and the at least one hydraulic ram mounted to the outer ring are directly opposed.
 4. The machine according to claim 1, wherein the inner and outer rings are oriented so that the at least one hydraulic ram mounted to the inner ring and the at least one hydraulic ram mounted to the outer ring are offset from each other.
 5. The machine according to claim 1, wherein the inner and outer rings are offset from each other.
 6. The machine according to claim 1, further comprising means for rotating the workpiece.
 7. The machine according to claim 1, wherein the inner ring comprises at least a pair of inner rings and the outer ring comprises at least a pair of outer rings, the at least a pair of inner and outer rings being arranged in at least a pair of sets of concentric inner and outer rings forming gaps therebetween, the at least a pair of sets connected together and having the gaps aligned with each other for receiving the workpiece.
 8. A machine for providing a cylindrical workpiece with a round circumference, comprising: an inner ring; an outer ring concentric with and surrounding the inner ring to form a gap between the inner and outer rings, the gap for receiving the workpiece between the inner and outer rings; at least a pair of hydraulic rams, at least one hydraulic ram mounted to each of the inner and outer rings so as to extend into the gap; and a vertically displaceable support connected to each of the inner and outer rings for moving the inner and outer rings up and down and rotating the inner and outer rings to align at least one of the at least a pair of hydraulic rams over an area of the workpiece.
 9. The machine according to claim 8, wherein each hydraulic ram comprises an hydraulic cylinder connected to a ram head.
 10. The machine according to claim 8, wherein the inner and outer rings are oriented so that the at least one hydraulic ram mounted to the inner ring and the at least one hydraulic ram mounted to the outer ring are directly opposed.
 11. The machine according to claim 8, wherein the inner and outer rings are oriented so that the at least one hydraulic ram mounted to the inner ring and the at least one hydraulic ram mounted to the outer ring are offset from each other.
 12. The machine according to claim 8, wherein the vertically displaceable support comprises rods attached to the inner and outer rings and connected to cables.
 13. A machine for providing a cylindrical workpiece with a round circumference, comprising: an inner ring; an outer ring concentric with and surrounding the inner ring to form a gap between the inner and outer rings, the gap for receiving the workpiece between the inner and outer rings; at least a pair of hydraulic rams, at least one hydraulic ram mounted to each of the inner and outer rings so as to extend into the gap; and a horizontally displaceable support connected to each of the inner and outer rings for moving the inner and outer rings right and left and rotating the inner and outer rings to align at least one of the at least a pair of hydraulic rams over an area of the workpiece.
 14. The machine according to claim 13, wherein the outer ring is segmented.
 15. The machine according to claim 14, wherein the outer ring comprises at least one segment, the at least one segment only partially surrounding the workpiece.
 16. The machine according to claim 13, wherein each hydraulic ram comprises an hydraulic cylinder connected to a ram head.
 17. The machine according to claim 13, wherein the inner and outer rings are oriented so that the at least one hydraulic ram mounted to the inner ring and the at least one hydraulic ram mounted to the outer ring are directly opposed.
 18. The machine according to claim 13, wherein the inner and outer rings are oriented so that the at least one hydraulic ram mounted to the inner ring and the at least one hydraulic ram mounted to the outer ring are offset from each other. 